J. Kissel, K. Izumi, S. Biscans (Remotely)

Through various back-channels, searching for reasons as to why the IFO is particularly noisy this evening, HAM2 and HAM3 ISI sensor correction came up in conversation. While we all thought the Sebastien had commissioned HAM2-ISI X sensor correction (see LHO aLOG 13964), yet we found that HAM2-ISI X sensor correction was OFF, and HAM3-ISI X sensor correction was ON, and has been ON with a gain of -0.5 since Thursday at ~3:30p PDT (1095114256, Sep 18 2014 22:24:00 UTC). 

Totally confused, we tried turning ON the the HAM2-ISI sensor correction, with the suggested gain of -10 from LHO aLOG 13964. This immediately caused the IFO to start shaking; clearly bad news. Naturally, given the level of confusion, we tried turning OFF HAM3 X sensor correction. 

I took long enough to write the above that Seb got back to us.
(1) HAM2-ISI -- the correct gain is -1, not -10. Though -10 was originally correct, and what he used to get the performance measurments in LHO aLOG 13964, it was errant because the GNDSTSINF Cal filters, a gain of ~10, had not been installed on the HAM-ISIs. Unfortunately, he reported this info in the SEI aLOG, and didn't cross reference, so we didn't catch it.
(2) HAM3-ISI -- Seb was teaching Jim and Hugh how to commission sensor correction using HAM3, and simple left what they had ON after Seb left Thursday afternoon. Seb is pretty confident that this correction is making things worse, so he recommends turning it OFF, and we have done so.

PLEASE PLEASE PLEASE -- If you're working on ANYTHING to do with the IFOs at the sites, information should be reported first and foremost in that site's aLOG. You're more than welcome to link the entry to any other aLOG, or send it out on an email list, or send it it in a post card to your mom, but it MUST go in the site aLOG first.

Sadly, after all the hub-bub, the IFO isn't working noticeably better. The investigation continues...